Which combination is most characteristic of disseminated intravascular coagulation?

• A. Thrombocytopenia, elevated fibrin degradation products, prolonged PT and aPTT
• B. Isolated hyperfibrinogenemia
• C. Normal platelets with shortened PT
• D. Thrombocytosis with normal coag tests

Answer: (B)

Disseminated intravascular coagulation is a consumption coagulopathy where widespread clotting in the microcirculation uses up platelets and coagulation factors while fibrinolysis breaks down those clots. This pattern shows up in the lab as low platelets, prolonged PT and aPTT, and elevated fibrin degradation products (such as D-dimer). Fibrinogen is typically consumed as well, so it is not expected to be elevated. So the most characteristic combination reflects both ongoing coagulation activation and active breakdown of clots: low platelets, prolonged clotting times, and high fibrin degradation products.

The other patterns don’t fit DIC. Isolated hyperfibrinogenemia points to an inflammatory or acute-phase state rather than a consumption coagulopathy. Normal platelets with a shortened PT would not reflect the consumptive process and can miss the bleeding risk. Thrombocytosis with normal coag tests suggests a reactive increase in platelets without the coagulopathy seen in DIC.